Overview
- Meteorological agencies reported a marked intensification of the Pacific El Niño signal in mid to late September, with the U.S. Climate Prediction Center assigning about a 75% probability that the event will reach exceptional strength for October–December 2026.
- Models and seasonal updates from ECMWF and Argentina’s Servicio Meteorológico Nacional show strong regional differences, with October likely drier than normal in provinces such as Santiago del Estero, Chaco, Santa Fe and Entre Ríos while the far northeast (Misiones, Corrientes) sees early above-normal rain.
- Forecast guidance shifts toward heavier rainfall in November and December, with ECMWF indicating possible December excesses exceeding 50 millimeters across central and northeastern Argentina that could raise flood and river-rise risks.
- Agricultural organisations and local authorities are issuing preparedness guidance focused on livestock moves, reducing herd density, and using higher ground and better-drained areas to limit losses from both short dry spells and later waterlogging.
- The World Meteorological Organization says effects could persist into early 2027 and forecasters flag the NOAA/CPC diagnostic update on 8 October as a key checkpoint for whether the extreme trajectory continues.